Jack Russells are not smart than other dogs.

Indeed, all dogs are of the same species, only differing by breed. Therefore, it is unlikely that any one breed of dog is significantly smarter than another. They may be trained in a certain way to enhance their thinking ability (perhaps), but they should possess no natural advantage over other breeds.

No, I think it comes down to training and care.

All dogs are quite good at solving problems, which gives credence to the traditional image of the cunning fox which is a member of the same family. Dogs descended from wolves which appear to have the biggest brains as they live in large family groups. However, they show this intelligence in different ways. Jack Russells are easy going and easy to train, which makes them seem more intelligent at times. In addition, other dog breeds have unique ways of showing their intelligence.

No, they are not.

Jack Russells are smart dogs, but there are many smart dog breeds. In fact, most dogs are much smarter than we give them credit for. Jack Russell Terriers are not really any smarter than any other dog breed, but they may have some unique traits and personality characteristics that other dogs do not share.

All dogs are intelligent.

I think that all breeds of dogs are intelligent. However, they show this intelligence in different ways. Jack Russells are easy going and easy to train, which makes them seem more intelligent at times. In addition, other dog breeds have unique ways of showing their intelligence. I think it comes down to training and care.